Research Training Program

Smithsonian Institution
National Museum of Natural History

PROJECT SUMMARY
1996

Matthew M. Unwin
Columbus State University
Columbus, Georgia
Elizabeth Zimmer, Ph.D.
Supervising Scientist
Department of Botany
Laboratory of Molecular Systematics
"This has been a good experience and has exposed me to all aspects of science. It has definitely helped prepare me for graduate school. "

Intergeneric relationships of the subtribe Munnozlinae in the Composite tribe Liabeae as estimated by molecular phylogenies

ABSTRACT
The sunflower family (Asteraceae) is one of the largest and most complex plant families. The unifying feature of this family tends to be the flower, which is usually compact, disc shaped, and has many smaller flowers on it. Members of the Asteraceae are incredibly diverse, ranging from small herbs to trees. They are found in a wide variety of habitats across the globe. Asters are also of economic importance; uses include food, medicines, pesticides, and ornamental plants. To understand how this plant family evolved would give many insights into the process of evolution. Unfortunately, working with this family is very difficult due to the sheer size and distribution of the family. In recent years, researchers have tended to focus on smaller groups or tribes within the Asteraceae. One such tribe is the Liabeae, whose members range from South to Central America, with their main concentration in the Andes Mountain range on the western coast of South America The Liabeae are relatively small, about 15 genera and 180 species. This small size along with a more concentrated distribution allows for a more manageable study group. Another change in the past few years has been the availability and use of molecular techniques. DNA can now be extracted from plants and amplified by means of the Polymerase Chain Reaction (PCR). Specific sequences of DNA can then be examined and comparisons made between them. Since specific regions of DNA tend to be highly conserved and others evolve more quickly, this allows for evolutionary inferences to be made. In this project, a subtribe within the Liabeae, the Munnoziinae, were examined by means of comparing the Internal Transcribed Spacer regions of the nuclear DNA. The Munnoziinae are thought to be a monophyletic group based on morphological research. By analyzing sequences of the Internal Transcribed Spacer regions (ITS) of the nuclear ribosomal DNA, our research shows that there is support for the monophyly of the Munnoziinae. This research has also shown that the ITS molecule is useful for this type of work. These results will be used in further studies of this subtribe and tribe.

Letter of Gratitude